Effective Cell Capture with Tetrapeptide-Functionalized Carbon Nanotubes and Dual Signal Amplification for Cytosensing and Evaluation of Cell Surface Carbohydrate

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• 作者：Wei Cheng ; Lin Ding ; Jianping Lei ; Shijia Ding ; Huangxian Ju
• 刊名：Analytical Chemistry
• 出版年：2008
• 出版时间：May 15, 2008
• 年：2008
• 卷：80
• 期：10
• 页码：3867 - 3872
• 全文大小：927K
• 年卷期：v.80,no.10(May 15, 2008)
• ISSN：1520-6882

文摘

A novel electrochemical cytosensing strategy was designed based on the specific recognition of integrin receptors on a cell surface to arginine−glycine−aspartic acid−serine (RGDS)-functionalized single-walled carbon nanotubes (SWNTs). The covalent conjugation of the RGDS tetrapeptide to SWNTs was proved with Raman and FT-IR spectra. The conjugated RGDS showed a predominant ability to capture cells on the electrode surface by the specific combination of RGD domains with integrin receptors. With the use of BGC-823 human gastric carcinoma cells (BGC cells) as a model, the cell surface mannosyl groups could specifically bind with horseradish peroxidase labeled concanavalin A, producing an electrochemical cytosensor. On the basis of the dual signal amplification of SWNTs and enzymatic catalysis, the cytosensor could respond down to 620 cells mL⁻¹ of BGC cells with a linear calibration range from 1.0 × 10³ to 1.0 × 10⁷ cells mL⁻¹, showing very high sensitivity. The dual signal amplification could be further used to evaluate the mannosyl groups on the cell surface, and the mannosyl groups on a single living intact BGC cell were detected to correspond to 5.3 × 10⁷ molecules of mannose. This strategy presents a promising platform for highly sensitive cytosensing and convenient evaluation of surface carbohydrates on living cells.